Pain is a multidimensional experience that combines sensory, affective, and cognitive factors, causing its treatment to be extremely complicated, expensive, and often ineffective. However, mindfulness meditation has been shown to be a cost-effective approach to decreasing both experimental and clinical pain. While these benefits have largely been seen over extensive, eight-week long training regimens, we have repeatedly shown that just four days of mindfulness meditation training can significantly reduce pain. These findings suggest that the pain-alleviating effects of mindfulness meditation are mediated through multiple psychological and neural mechanisms. However, the specific physiological mechanisms through which mindfulness meditation reduces pain remain poorly characterized. Interestingly, mindfulness meditation has been demonstrated to directly increase high frequency heart rate variability (HF HRV), a marker of parasympathetic activity, and extensive preliminary evidence demonstrates a relationship between parasympathetic dysregulation and the severity of clinical and experimental pain. Furthermore, while mindfulness meditation-induced analgesia engages multiple brain mechanisms, we have found that activation in the rostral anterior cingulate cortex (ACC) is directly associated with greater reductions in pain intensity ratings. Importantly, greater meditation-induced activation of the ACC is also associated with greater HF HRV. However, it remains unknown if the pain-relieving effects of mindfulness meditation are associated with changes in HF HRV. This fellowship will test the hypothesis that the analgesic effects of mindfulness meditation are correlated with increases in parasympathetic activity, as measured by HF HRV. The knowledge gained from this fellowship will provide mechanistic insight into the pain-relieving effects of mindfulness meditation, an important concern when considering this intervention as a treatment for clinical pain. The research and training plan outlined in this fellowship will provide the applicant with career-oriented mentorship, a robust statistical analysis skillset, and the psychophysical/physiological research experience necessary to succeed as a successful and independent physician-scientist.